Stop #3, Esker
Look ahead of you to the south and you will see long mounds 5’-10’ or so tall snaking their way across the landscape for some 100’ or more. These are eskers, and are formed when meltwater on the glacier’s surface drains through a hole to the underside of the glacier and twists and turns to find a way out. The stream, usually laden with debris, slows and deposits its load into the rounded mounds you see here.
Did you notice that the trail between the parking lot and here had numerous sharp rises and descents? You were walking over or on several eskers. As you proceed on the walk you will notice numerous eskers snaking through the landscape.
Fascinated with eskers? Explore SVT’s and the Town of Wayland's School House Pond/Castle Hill in Wayland or the Esker Loop in the Shirley, Mass. section of the Oxbow Wild Refuge. Each is a large esker that forms a magnificent cliff composed of glacial debris called till.
Continue on 300 yds. to stop #4, keeping left at intersections F and E.